Results 71 to 80 of about 1,056,070 (342)
Electroluminescence and Franz–Keldysh Modulation Observed in Sn/Ge Multi‐Quantum Wells
Advanced Optical Materials, EarlyView.We investigate the optoelectronic properties of PIN diodes based on ultrathin α‐Sn/Ge multiple quantum film structures, fabricated by molecular beam epitaxy, both experimentally and theoretically. The samples exhibit a light emission spectrum in the short‐wavelength infrared range with two transitions. Furthermore, when operating as a photodetector, we
Michael Oehme +9 more
wiley +1 more source
Complex dynamics of drill-strings: Theory and experiments
MATEC Web of Conferences, 2018 We investigate complex drill-string dynamics in a downhole drilling where strong nonlinear interactions between various types of vibration take place.
Wiercigroch Marian +3 more
doaj +1 more source
Analysis of drilling vibration characteristics of anchoring system in coal mine
Scientific Reports, 2023 A new type of parallel operation unit for excavating and supporting anchors is proposed to address the issue of imbalanced excavation anchor ratio in coal mines. By equipping a straddle type anchoring drilling rig group, the synchronous parallel and fast
Miao Xie +5 more
doaj +1 more source
Push-and-Twist Drillstring Assemblies [PDF]
, 2017 Deep drilling using a rigid drillstring requires the assembly and disassembly of multiple drill pipes. The interfaces between these pipes provide a challenge for automation because they must transmit large drilling forces and movements while, at the same
Firstbrook, David G. +5 more
core
The Dale Oil Field, Caldwell County, Texas [PDF]
, 1930 Geological ...
Hancock, James Martin
core +1 more source
Advanced Science, EarlyView.Bacterial α‐diversity decreases, but stochasticity and community stability increase across the 15 m‐depth vertical profiles and along the degraded gradient within the active layer. The abundance and interaction of core taxa mainly control community stability in the active and permafrost layers, respectively.
Shengyun Chen +13 more
wiley +1 more source
Study on Dynamic Characteristics of drill String-drill Bit-rock System
Shiyou jixie, 2017 Drill bit, drill string and rock system as a whole, has coupled and interacted dynamic characteristics, which is neglected in most of researches. In view of this, considering the coupling of axial and lateral torsion of the lower drilling tool and the ...
Hu Zhiqiang +3 more
doaj
Известия высших учебных заведений: Геология и разведка, 2016 The paper considers the technological features of rock-destroying instruments (drill bits, drill crowns) of PDC series, concerning their vibration during drilling in rocks, variable in mechanical properties. A factor is presented, which characterizes the
M. S. Frolova
doaj +1 more source
Dust Control in Rock Drilling [PDF]
American Journal of Public Health and the Nations Health, 1940 THE importance of silicosis as an occupational disease has been demonstrated in many industries. Such investigations have shown rock drilling in hard-rock mining and other drilling operations to be hazardous, even including open drilling in quarries, road construction, and building excavation.
L, Greenburg +3 more
openaire +2 more sources
Prediction of the temperature of a drill in drilling lunar rock simulant in a vacuum
, 2017 In this article, the temperature of a sampling drill in drilling lunar rock simulant in a high-vacuum environment was studied. The thermal problem was viewed as a one dimensional transient heat transfer problem in a semi-infinite object.
Jinsheng Cui +4 more
semanticscholar +1 more source